Common cold can dramatically increase heart attack risk

Mark Waghorn

Catching a cold raises your risk of suffering a heart attack by 13 times, according to new research.

And the danger from a more severe bug like the flu, bronchitis or pneumonia is even greater - increasing the likelihood 17-fold.

The latest study could explain why more people die from heart disease in winter.

The dramatic rise in risk peaks in the first seven days of being struck down - but patients remain endangered for a full month, say scientists.

It's believed upper and lower respiratory tract infections - which respectively affect the nose and throat or the lungs - can damage vessels or arteries.

This may lead to a clot that cuts off blood supply to the heart.

Many studies have shown the link between temperature and heart attacks but experts have been unable to explain the reason.

The increase in deaths from cardiovascular illness in cold periods was previously blamed on people doing physically demanding tasks, like shovelling snow.

Now an association between respiratory infections and heart attacks caused by blood clots has been reported for the first time in Internal Medicine Journal.

Senior author Prof Geoffrey Tofler, a cardiologist from Sydney University and Heart Research Australia, said: "Our findings confirm what has been suggested in prior studies that a respiratory infection can act as a trigger for a heart attack.

"The data showed the increased risk of a heart attack isn't necessarily just at the beginning of respiratory symptoms, it peaks in the first 7 days and gradually reduces but remains elevated for one month."

The study found 17 per cent of participants had reported symptoms of respiratory infection within 7 days of the heart attack - and 21 per cent within 31 days.

Patients were interviewed about their activities before the onset of their heart attack, including if they experienced a recent "flu-like illness with fever and sore throat".

They were considered affected if they reported sore throat, cough, fever, sinus pain, flu-like symptoms, or if they reported a diagnosis of pneumonia or bronchitis.

A second analysis was among those with symptoms restricted to the upper respiratory tract, which included the common cold, pharyngitis, rhinitis and sinusitis.